So the reason that vengeance is a challenging build to set up well is that vengeance only multiplies the physical damage of your attack by a bajillion, all elemental damage is ignored and added on at the end. So if you want vengeance itself to do high damage, you need to be working on your actual weapon damage without elemental mods. If you think about it, you're basically trying to add a bunch of elemental damage on top of your attack, without taking advantage of vengeance' damage. That leads me to thinking about alternative attacks - getting attacks/second up and just letting all this added damage and procs happen each hit instead of on a slow ass hit. What you're building here makes more sense to me as gear for a conviction zealer, something where you're just trying to land a ton of hits and using conviction and auras to get the dps.